Design and Development of Mono Leaf Spring by using Composite Material (Epoxy-Carbon Fiber)

Kalyani Sudhir Kulkarni, Prof. V.J.Khot

Bending stress, composite leaf spring, carbon epoxy, FRP, NASTRAN / ANSYS software.

According to the demand of recent world, the more concentration is on weight reduction in automobiles. The possible weight reductions are wheel assembly, axles, and part of the weight of suspension spring and shock absorbers. The leaf spring accounts for 10-20% of the un-sprung weight. The composite materials made it possible to reduce the weight of machine element without any reduction of the load carrying capacity. Because of composite material's high elastic strain energy storage capacity and high strength-to weight ratio compared with those of steel. FRP spring also have excellent fatigue resistance and durability. But the weight reduction of the leaf spring is achieved not only by material replacement but also by design optimization. Weight reduction has been the focus of automobile manufacturers in the present scenario. The replacement of steel with optimally designed composite leaf spring can provide 75%-78% weight reduction. The material selected is carbon epoxy against conventional steel. The optimization study consists of use of software's such as NASTRAN / ANSYS software. The experimentation on UTM is carried out and results are compared. Moreover, the composite leaf spring has lower stresses compared to steel spring. All these will result in fuel saving which will make countries energy independent because fuel saved is fuel produced.